The present invention relates to apparatus for stacking rigid magnetic discs, usually during manufacture, so that the discs do not come into contact with one another.
Rigid magnetic discs are in common use in computer storage and retrieval units. Such discs typically comprise a circular aluminum plate having a central aperture, and both faces of the plate are coated with a magnetic substance to provide a pair of magnetic recording surfaces. Such discs are capable of extremely fine resolution so that a large volume of data can be magnetically stored on a single disc. To preserve such resolution, great care is required in handling the discs so that they do not contact one another or a foreign object. Any such contact significantly degrades the quality of the magnetic coating and ruins the disc.
A variety of relatively complex devices have been developed to handle rigid magnetic discs while they are being manufactured. However, most such devices involve a screw thread arrangement to capture the disc. This type of device is quite sensitive to the size of the central aperture of the disc. This aperture often has a fairly wide tolerance, and such prior devices are sometimes inadequate to prevent the discs from contacting one another, an occurrence which ruins both discs. Moreover, such devices are usually not failsafe and the user of the device can, by mistake, cause the discs to contact one another.